This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.

The pthread_attr_getschedpolicy() and pthread_attr_setschedpolicy()
functions, respectively, shall get and set the schedpolicy attribute
in the attr argument.
The supported values of policy shall include SCHED_FIFO, SCHED_RR,
and SCHED_OTHER, which are defined in the <sched.h> header. When
threads executing with the scheduling policy SCHED_FIFO, SCHED_RR, or
SCHED_SPORADIC are waiting on a mutex, they shall acquire the mutex
in priority order when the mutex is unlocked.
The behavior is undefined if the value specified by the attr argument
to pthread_attr_getschedpolicy() or pthread_attr_setschedpolicy()
does not refer to an initialized thread attributes object.

The pthread_attr_setschedpolicy() function shall fail if:
ENOTSUP
An attempt was made to set the attribute to an unsupported
value.
The pthread_attr_setschedpolicy() function may fail if:
EINVAL The value of policy is not valid.
These functions shall not return an error code of [EINTR].
The following sections are informative.

After these attributes have been set, a thread can be created with
the specified attributes using pthread_create(). Using these
routines does not affect the current running thread.
See Section 2.9.4, Thread Scheduling for further details on thread
scheduling attributes and their default settings.

If an implementation detects that the value specified by the attr
argument to pthread_attr_getschedpolicy() or
pthread_attr_setschedpolicy() does not refer to an initialized thread
attributes object, it is recommended that the function should fail
and report an [EINVAL] error.

Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) In the event of any discrepancy between this version and
the original IEEE and The Open Group Standard, the original IEEE and
The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 PTHREAD_ATTR_GETSCHEDPOLICY(3P)